Washingtonpost.com on Thursday unveiled a study done in conjunction with Nielsen//NetRatings that showed affluent customers are best reached online.

The research, done via a study of nearly 1,000 washingtonpost.com users, found that affluent customers -- those making over $100,000 annually spend a good portion of their day online. The site seized on this fact as further evidence of online publishers' assertion that work hours are the Internet's "prime time."

"We were looking for confirmation of what all of us in the industry suspect, which is that so many of the people are online, especially during the daytime, are a high-quality audience," said Chris Schroeder, washingtpost.com's chief executive.

The study found that nearly all affluent consumers use the Internet for research before buying a product, and the Internet tied newspapers as the media advertising chosen as most influential. Over half of the affluent said they were influenced by Internet advertising to make a purchase in the past six months.

"The Internet is not simply being used as an electronic shopping mall, but as a primary resource for understanding and researching decisions," said Carolyn Clark, a senior Internet analyst at Nielsen//NetRatings.

For example, more than 90 percent of respondents said they used the Internet when making a purchase decision involving an automobile, computer or travel. In those categories, in addition to computers and home electronics, half of consumers spend more than one hour researching, according to the study.

Unsurprisingly, the survey found that the Internet is the dominant media vehicle for affluent consumers during the day.

Washingtonpost.com and other advertisers in the Online Publishers Association (OPA) have tried to leverage the Internet's strength in the day hours into more marketing dollars. Schroeder said the site had done a few dayparting advertisements, including a recent promotion from a food retailer to offer a coupon online just before lunchtime.

Still, marketers have only just begun to experiment with dayparting. To spur this along, the OPA recently published guidelines that divided the day into five distinct parts for marketing purposes online.

"I think dayparting is only in its infancy and folks are beginning to focus on it," Schroeder said.

The findings largely echo those of a recent study done by the Wall Street Journal Online and eMarketer, which found that the Internet is the place for marketers to connect with well-educated and well-off consumers. According to that study, 70 percent of daytime Internet users have college degrees and half have a household income topping $75,000.